/* ============================================================
   case-study.css — shared chrome for every work/*.html page
   loaded after base.css; page-unique visuals stay inline
   ============================================================ */

:root {
    --wrap: 58rem;
}

/* ---------- Nav ---------- */
.nav {
    position: sticky;
    top: 0;
    z-index: 10;
    background: rgba(251, 249, 246, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--line);
}

.nav-inner {
    max-width: var(--wrap);
    margin-inline: auto;
    padding-inline: 1.25rem;
    height: 4.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

@media (min-width: 768px) {
    .nav-inner {
        padding-inline: 2rem;
    }
}

.nav-logo {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1.0625rem;
    letter-spacing: -0.01em;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-mono {
    width: 2rem;
    height: 2rem;
    border-radius: 999px;
    background: var(--green);
    color: #fff;
    display: grid;
    place-items: center;
    font-size: 0.875rem;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--ink-soft);
    transition: color 0.2s ease;
}

.back-link:hover {
    color: var(--green);
}

/* ---------- Hero ---------- */
.cs-hero {
    padding-block: 4rem 3rem;
}

@media (min-width: 768px) {
    .cs-hero {
        padding-block: 5.5rem 3.5rem;
    }
}

.cs-title {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 2.5rem;
    letter-spacing: -0.02em;
    line-height: 1.05;
    margin-top: 0.75rem;
}

@media (min-width: 768px) {
    .cs-title {
        font-size: 3.5rem;
    }
}

.cs-subtitle {
    font-size: 1.125rem;
    color: var(--ink-soft);
    margin-top: 0.75rem;
}

.cs-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1.5rem;
}

.tag-pill {
    font-size: 0.75rem;
    border-radius: 999px;
    background: var(--surface);
    border: 1px solid var(--line);
    padding: 0.25rem 0.75rem;
    color: var(--ink-soft);
}

.cs-intro {
    max-width: 40rem;
    margin-top: 2rem;
    font-size: 1.125rem;
    color: var(--ink-body);
    line-height: 1.7;
}

/* ---------- Stats strip ---------- */
.cs-stats {
    padding-block: 2rem 1rem;
}

.cs-stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
}

.stat-tile {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 1.25rem;
    padding: 1.5rem 1.75rem;
    box-shadow: 0 4px 24px rgba(28, 25, 23, 0.05);
}

.stat-value {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1.875rem;
    letter-spacing: -0.01em;
    color: var(--green);
}

.stat-label {
    font-size: 0.8125rem;
    color: var(--ink-soft);
    margin-top: 0.375rem;
    line-height: 1.4;
}

/* ---------- Chapters ---------- */
.chapter {
    padding-block: 4.5rem;
    border-top: 1px solid var(--line);
    scroll-margin-top: 4.5rem;
}

.chapter-head {
    max-width: none;
}

.chapter-kicker {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.chapter-num {
    font-family: var(--mono);
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--sand);
    letter-spacing: 0.05em;
}

.chapter-cat {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.16em;
    color: var(--ink-soft);
    font-weight: 600;
}

.chapter-title {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1.75rem;
    letter-spacing: -0.01em;
    margin-top: 0.625rem;
}

@media (min-width: 768px) {
    .chapter-title {
        font-size: 2.125rem;
    }
}

.chapter-text {
    margin-top: 1rem;
    color: var(--ink-body);
    line-height: 1.75;
    font-size: 1.0625rem;
}

.chapter-visual {
    margin-top: 2.5rem;
}

/* ---------- Extra highlights ---------- */
.cs-extra {
    margin-top: 2rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 1.25rem;
    padding: 1.75rem;
}

.cs-extra-title {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1.0625rem;
    margin-bottom: 1rem;
}

.cs-extra-list {
    display: flex;
    flex-direction: column;
    gap: 0.625rem;
}

.cs-extra-list li {
    position: relative;
    padding-left: 1rem;
    color: var(--ink-body);
    font-size: 0.9375rem;
    line-height: 1.6;
}

.cs-extra-list .bullet {
    position: absolute;
    left: 0;
    top: 0.55rem;
    width: 0.3125rem;
    height: 0.3125rem;
    border-radius: 999px;
    background: var(--sand);
}

/* ---------- Case-study navigation ---------- */
.cs-case-nav {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
    margin-top: 3.5rem;
    margin-bottom: 6rem;
}

@media (min-width: 640px) {
    .cs-case-nav {
        grid-template-columns: 1fr 1fr;
    }
}

.cs-case-nav-btn {
    display: flex;
    align-items: center;
    gap: 0.875rem;
    padding: 1.25rem 1.5rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 1.25rem;
    box-shadow: 0 4px 24px rgba(28, 25, 23, 0.05);
    transition: border-color 0.2s ease, transform 0.2s ease;
}

a.cs-case-nav-btn:hover {
    border-color: var(--green);
    transform: translateY(-2px);
}

.cs-case-nav-next {
    justify-content: flex-end;
    text-align: right;
}

.cs-case-nav-icon {
    width: 2.25rem;
    height: 2.25rem;
    border-radius: 999px;
    background: rgba(42, 100, 81, 0.1);
    color: var(--green);
    display: grid;
    place-items: center;
    flex-shrink: 0;
}

.cs-case-nav-label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--ink-soft);
    font-weight: 600;
}

.cs-case-nav-title {
    display: block;
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1rem;
    margin-top: 0.1875rem;
    color: var(--ink);
}

.cs-case-nav-btn.disabled {
    opacity: 0.45;
    cursor: default;
}

.cs-case-nav-btn.disabled .cs-case-nav-icon {
    background: var(--bg);
    color: var(--ink-soft);
}